1. The Born-Oppenheimer Separation

2. The Born-Oppenheimer Separation
Molecules
electronic transitions
E > cm-1

3. The Born-Oppenheimer Separation
Molecules
electronic transitions
E > cm-1
Vibrational transitions
E = cm-1

4. The Born-Oppenheimer Separation
Molecules
electronic transitions
E > cm-1
Vibrational transitions
E = cm-1
Rotational transitions
E = 0.1 – 100 cm-1

5. The Born-Oppenheimer Separation
H = Hel + Hvib + Hrot+ …

6. The Born-Oppenheimer Separation
H = Hel + Hvib + Hrot+ …
 = el vib rot …

7. The Born-Oppenheimer Separation
H = Hel + Hvib + Hrot+ …
 = el vib rot …  = i i

8. The Born-Oppenheimer Separation
H = Hel + Hvib + Hrot+ …
 = el vib rot …  = i i
E = Eel + Evib + Erot +…

9. The Born-Oppenheimer Separation
H = Hel + Hvib + Hrot+ …
 = el vib rot …  = i i
E = Eel + Evib + Erot +… E= i Ei
Harry Kroto 2004

10. E(r)
H + H
v”=3 2 1
r 

11. Excited electronic states - often many
H + H*
v’=3 2 1
E(r)
H + H
v”=3 2 1
r 

12. Nuclear Energies
H + H
E(r)
Chemical Energies
Rotational levels
r 

13. E(r) H + H r  Continuum wavefunction of a dissociating state
Rotational levels
r 

15. H + H
E(r)
Rotational levels
r 

16. C* + N
E(r)
v’= 0
C + N
v”=3 2 1
r 